Method of dyeing acrylic fibers



GENICHI HAYASHI ETAL 3,545,914

METHOD OF DYEING ACRYLIC FIBERS Filed March 24, 1967 Fig.1

am I50 0 re 40 so (M) (but) (76c) (80 (We) ammo u Im/surons:

(eon) (rot) (set) (you (we) o e) u waemm HRYASH! ml roman 00 0B0 81 wwmmxmw mad,

n'TToKN Y United States Patent Office 3,545,914 METHOD OF DYEING ACRYLIC FIBERS Genichi Hayashi and Tornoji kubo, Saidaiji, Japan, assignors to Japan Exlan Company Limited, Osaka,

Japan Filed Mar. 24, 1967, Ser. No. 625,845 Claims priority, application Japan, Mar. 30, 1966, 4 20,175 Int. Cl. D06p 3/70 US. Cl. 8-169 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a method of even and fast dyeing of acrylic fibers with a cationic dye and more particularly to a method of evenly dyeing and fast dyeing acrylic fibers with a cationic dye by adding at least one compound selected from saturated and unsaturated monocarboxylic acid salts having not less than 10 carbon atoms in the alkyl radical and saturated dicarboxylic acid salts having not less than 4 carbon atoms in the alkyl radical to a dyeing bath and while varying the pH of the dyeing bath.

As an evenly dyeing method, according to The American Dyestutt Reporter vol. 49, pp. 272 to 284 (1960), there is described a method of dyeing acrylic fibers with a cationic dye by adding an anionic dyeing assistant to the dyeing bath so that it may once form a complex salt with the cationic dye in the dyeing bath and then ele ating the temperature of the bath so that the cationic dye dissociated on the surface of the fibers may be gradually deposited on the fibers. That is to say, it is a dyeing method called an IT process wherein Irgasol DA (produced by J. R. Geigy, Switzerland) is added as an anionic dyeing assistant so that it may form a complex salt with the cationic dye, further Tinegal NA (produced by J. R. Geigy, Switzerland) is added as a nonionic dyeing assistant to disperse said complex salt and the temperature is gradually elevated. However, according to this IT process, in the case of dyeing acrylic fibers with a cationic dye, the dyeing rate will reduce and the evenly dyeing can be realized to a considerable extent but, as demerits, the dye will remain in the residual bath after the dyeing and will not be completely adsorbed in the fibers, the higher the dye concentration, the larger the amount of the remaining dye and such is not desirable also to economy. That is to say, Irgasol DA is a formalin condensate of naphthalene sulfonic acid, and therefore form a secure bond with the cationic dye and will be in an equilibrium relation with the dye bonding force to the acid group (dye site) of the acrylic fibers even in the end period of the dyeing. As a result, the cationic dye will remain at a fixed rate in the dyeing bath.

Further, a cationic retarded dyeing method is usually well utilized to evenly dyeing acrylic fibers. However, according to this method, as the retarder as Well as the cationic dye is adsorbed in the fibers, the light-fastness, laundry-fastness, stainproofness by hot-water treatment and dry heat-fastness will be often lower and the hand will be adversely affected thereby.

Generally, as a method of dyeing acrylic synthetic 3,545,914 Patented Dec. 8, 1970 fibers, there is usually adopted a method wherein the fibers are immersed in a dyeing bath, the dyeing bath temperature is gradually elevated from 60 C. to 100 C. in 40 to 50 minutes to effect evenly dyeing so that the dye may be gradually deposited on the fibers and further, after the dyeing bath temperature reaches 100 C., the dyeing bath temperature of 100 C. is kept generally for 20 to 40 minutes somewhat different depending on the kind of the dye so that the dye may be well diffused within the fibers. However, when the dyeing is carried out by adding only the cationic dye into the dyeing bath, the dyeing rate of the dye for the fibers will be so high that, when the dyeing temperature rises to to C., almost all the dye in the dyeing bath will be adsorbed in the fibers, therefore no even dyeing will be attained but uneven dyeing will result. Therefore, in order to reduce the dyeing rate, it is necessary to add a retarder. In the case of using a cationic dye, the IT process or cationic retarded dyeing method has been suggested. But such method has such demerits as are described above.

Therefore, an object of the present invention is to provide a dyeing method wherein the above mentioned demerits are overcome and a fast and even dyeing can be eifected with a cationic dye.

The object of the present invention is attained by a process wherein, in dyeing with a cationic dye, at least one compound selected from the group consisting of salts of unsaturated and saturated monocar-boxylic acids having not less than 10 carbon atoms in the alkyl radical and salts of dicarboxylic acids having not less than 4 carbon atoms in the alkyl radical is added as an anionic dyeing assistant to a dyeing bath so that a complex salt may be formed with the cationic dye, further a nonionic surface active agent is added to disperse said complex salt, and the pH is adjusted to be 8 to 9 in the initial period of the dyeing, and then gradually reduced and is made 3 to 4 in the end period of the dyeing.

The proper amount of the saturated or unsaturated monocarboxylic acid salt and/or the saturated dicarboxylic acid salt to be added to the dyeing bath in the present invention is 5 to 10% on the weight of the fibers. Further, in order to prevent a complex salt formed by the reaction of such carboxylic acid salt with the cationic dye from tending to come to precipitate, it is necessary to add 1 g./liter of a nonionic active agent as a precipitation preventing agent or a dispersing agent into the dyeing bath. Here, in case the concentration of such carboxylic acid salt (calculated as a free acid) in the dyeing bath is lower than 5% on the weight of the fibers, the etfect of the present invention will not be well obtained. In case it is higher than 10% on the weight of the fibers, the effect of the present invention will not be adversely infiuenced but there will be a waste in economy.

In order to perfectly realize the efiect or merit of the present invention, a cationic dye and the above mentioned carboxylic acid salt are added to a dyeing bath, and the pH is adjusted to be 8 to 9 by adding an aqueous solution of such alkali as, for example, caustic soda, caustic potash or ammonia so that a complex salt of the cationic dye and the carboxylic acid salt may be formed. Further, a nonionic surface active agent is added to prevent the precipitation of said complex salt, Then acrylic fibers are immersed in the dyeing bath and the dyeing bath temperature is gradually elevated to C. in 40 to 50 minutes. Thus, as the dye and the carboxylic acid salt have formed a complex salt, a retarded dyeing effect will be obtained and an evenly dyeing can be attained in the case of dyeing by gradually elevating the dyeing bath temperature from 60 C. to 100 C. Further, even if the dyeing bath temperature of 100 C. is kept as it is, as the cationic dye and the carboxylic acid salt have formed a secure bond, an equilibrium relation with the dye bonding force to the acid group (dye site) of the acrylic fibers will be produced and, as a result, the dye will be no longer adsorbed in the fibers. Therefore, the addition of dilute sulfuric acid or the like must be started within at least minutes after the dyeing bath temperature becomes 100 C., the dilute sulfuric acid must be further gradually added while the dyeing bath temperature is kept at 100 C. during the time until the dyeing is completed and the pH of the dyeing bath must be finally reduced to 3 to 4. That is to say, when the complex salt of the cationic dye and the carboxylic acid salt is degraded gradually by gradually reducing pH so that the free cationic dye may be gradually adsorbed in the fibers and finally almost all the cationic dye may be adsorbed in the fibers, the effect of the present invention will be satisfactorily attained.

Thus when the pH in the dyeing bath is high, such carboxylic acid salt will be so securely bonded with the cationic dye that the rate of dyeing to the fibers will be H controlled but, when the pH is gradually reduced, the bonding force of the cationic dye and the carboxylic acid salt will gradually become weak. Thus, at a pH of 3 to 4, under the dyeing bath condition of 100 C., the cationic dye will be perfectly bonded with the fibers and almost all the dye will be exhausted.

Therefore, if dyeing is carried out while controlling the dyeing rate by adjusting the pH to be 8-9 to in the initial step of the dyeing and then the pH is reduced by gradually adding such strong acid as, for example, sulfuric acid, the dyeing rate of the cationic dye will be in an ideal state, the cationic dye in the dyeing bath will be perfectly bonded with the fibers, even dyeing will be obtained and a dyed product high in the fastness will be obtained.

Examples of saturated monocarboxylic acid salts of not less than 10 carbon atoms in the alkyl radical to be used in the present invention are potassium salts, sodium salts and ammonium salts of undecylic acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, etc.

Examples of unsaturated monocarboxylic acid salts having not less than 10 carbon atoms in the alkyl group are potassium salts, sodium salts or ammonium salts of undecenoic acid, dodecenoic acid, tetradecenoic acid, hexadecenoic acid, octadecenoic acid, etc.

The saturated dicarboxylic acid salts of not less than 4 carbon atoms in the alkyl radical are potassium salts, sodium salts and ammonium salts of adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid undecandioic acid, dodecanedioic acid, brasylic acid and tetradecanedioic acid, and others.

The nonionic active agents to be used in the present invention may be exemplified as Noygen HC (polyoxyethylene lauryl ether; produced by Daichi Industrial and Pharmaceutical Co., Ltd.); Riponox S (polyoxyethylene alkyl ether; produced by Lion Oil and Fat Co., Ltd.); Emarox EOR (polyoxyetheylene alkyl ether; produced by Yoshimura Oil and Fat Co., Ltd.); Noniolite BP- (polyoxyethylene alkyl aryl ether; produced by Kyoeisha Oil and Fat Co., Ltd.), Atlas MYRJ, Atlas Chemical Industries, Inc.); Atlas G 2127 (polyoxyethylene laurate; produced by Atlas Chemical Industries, Inc.), etc.

The invention will be described in more detail by re ferring to the following examples wherein all percentages are by weight unless otherwise specified. Further, Color Index (C.I.) given in these examples are taken from Color Indes, 2nd Edition 1956 and Supplement, 1963 published by The American Association of Textile Chemists and Colorists, Lowell, Mass., U.S.A. and The Society of Dyers and Colourists, Bradford, England, and in the examples various fastnesses were determined as follows:

Light-fastnessAATCC 16Al964 Laundry-fastness--AATCC 36-1965 4 EXAMPLE 1 (I) O1. Basic Blue 3 (Cl. No. 51005) in an amount of 1% on the weight of fibers (which percentage shall be abbreviated as percent OWF hereinafter) and ammonium oleate in an amount of 5% OWF as calculated as converted to oleic acid were added to a dyeing bath. The pH of the bath was adjusted to be 8 by adding ammoniua water. Further, 1 g./liter of Noygen HC (polyoxyethylene lauryl ether) was added to the dyeing bath. Then, acrylic fibers (sulfonic acid group content 0.4%) were immersed in the bath at a bath ratio of 1/ 100. The dyeing bath temperature was gradually elevated from 60 C. to C. in 40 minutes and was further kept at 100 C. for 20 minutes to dye the fibers. In such case, when the dyeing bath temperature reached 100 C., dilute sulfuric acid was gradually added. In 20 minutes or finally, the pH was adjusted to be 3.5.

(II) 1% OWF C.I. Basic Blue 3 (Cl. No. 51005), 2% OWF Irgasol DA and 2% OWF Tinegal NA were added to a dyeing bath. The same sample as in (I) above was immersed in the dyeing bath at a bath ratio of 1/100. The dyeing bath temperature was gradually elevated from 60 C. to 100 C. in 40 minutes and was further kept at 100 C. for 20 minutes to dye the fibers.

(III) The same sample as in (I) above was immersed in a dyeing bath under the conditions of 1% OWF C.I. Basic Blue 3 (Cl. No. 51005) and a bath ratio of 1/100. The dyeing bath temperature was gradually elevated from 60 C. to 100 C. in 40 minutes and was further kept at 100 C. for 20 minutes to dye the fibers.

Here, (I) is a method of the present invention, (II) is a dyeing method by the known IT process and (III) is a dyeing method by using no assistant at all.

The reflection rates of the dyed products in the above mentioned dyeing processes (I), (II) and (III) were determined with a self-recording visible spectrophotometer (Model EPR-II made by Hitachi Ltd.) and the dye concentrations F(R) on the fibers were determined according to the Formula 1:

wherein R is a reflection rate of a dyed product at the maximum wavelength point and R is a reflection rate of an undyed sample.

Now, when the dye concentration on the dyed product completely dyed by the process (III) or having completely absorbed the dye in the dyeing bath was F(R,,) and the dye concentration on another dyed product was F(R the comparative concentration C of each dyed product was determined from the Formula 2:

(2) MR.) X100 The relations of the dyeing time and dye concentration on the dyed products in the respective dyeing methods (I), (II) and (III) above as calculated from the Formulae 1 and 2 are shown in FIG. 1. As evident from FIG. 1, it is shown that, in the method (III) wherein only the dye but no assistant at all was used, the dyeing rate was so high that no even dyeing was obtained, that, in the method (II) or the IT process, the final dye concentration was low and a large amount of the dye was present in the residual bath and that, in the method (I) or the method of the present invention, a favorable or ideal dyeing rate was obtained and the final dye concentration was also high.

EXAMPLE 2 10% OWF ammonium oleate and l g./liter of Noniolite BP-15 (polyoxyethylene alkyl aryl ether) were added into a mixed dyeing bath of 1% OWF Maxilon Red BL (produced by J. R. Geigy, Switzerland) and 1% OWF Maxilon Blue GL (produced by I. R. Geigy, Switzerland). The pH of the dyeing bath was adjusted to be 8 with ammonia water. A hosiery cloth of acrylic fibers (sulfonic C (percent) acid group content 0.4%) was immersed in the dyeing bath at a bath ratio of U100. The dyeing bath temperature was gradually elevated from 60 C. to 100 C. in 45 minutes and was further kept at 100 C. for 40 minutes to dye the cloth. After the dyeing bath temperature reached 100 C., a dilute aqueous solution of sulfuric acid was gradually added to the dyeing bath so that the pH might be 3.5 in 40 minutes. Then the cloth was gradually cooled, washed with water and dried. The thus obtained dyed product showed a clear even violet color. The dye concentration was 91.4%. On the other hand, the dye concentration on the dyed product dyed by the IT process was shown to be 60.5%. As regards the fastness of the dyed product in this example, its light-fastness was the Class 7, its laundry-fastness was Class 5 and they were the same as in the dyed product by the IT process.

EXAMPLE 3 7% OWF potassium stearate was added into a mixed dyeing bath of 1% OWF C.I. Basic Blue 3 (C.I. No. 51005) and 1% OWF C.I. Basic Yellow 24. One gram per liter of Noygen HC (polyoxyethylene lauryl ether) was further added to the bath. The pH of the bath was adjusted to be 8 with an aqueous solution of caustic soda. A bulky yarn of acrylic fibers (sulfonic acid group content 0.4%) was immersed in the dyeing bath at a bath ratio of 1/100. The dyeing bath temperature was gradually elevated from 60 C. to 100 C. in 45 minutes and was kept at 100 C. for 40 minutes to dye the yarn. In minutes after 100 C. was reached, dilute sulfuric acid was gradually added into the dyeing bath so that the pH might be finally 3.5. Then the yarn was gradually cooled, was washed with water and was dried. The thus obtained dyed product had been evenly dyed and showed a clear green color. Its dye concentration was shown to be 98.5%. Its light-fastness was Class 7 and its laundry-fastness was Class 5. On the other hand, the dye concentration on the dyed product dyed by the IT process was shown to be 60.3%. Its light-fastness was Class 7 and its laundryfastness was Class 5.

EXAMPLE 4 C.I. Basic Blue 3 (C.I. No. 51005) to be 2% OWF and sodium myristate to be 5% OWF were added into a dyeing bath. The pH of the dyeing bath Was adjusted to be 8 with an aqueous solution of caustic potassium. 1 g./ liter of Noygen HC (polyoxyethylene lauryl ether) was added as a disperse agent. A bulky yarn of acrylic fibers (sulfonic acid group content 0.4%) was dyed at a bath ratio of U100. After the fibers were immersed in the dyeing bath, the dyeing bath temperature was gradually elevated from 60 C. to 100 C. in 45 minutes and was then kept at 100 C. for 40 minutes to dye the fibers. In 10 minutes after the dyeing bath temperature reached 100 C., a dilute aqueous solution of sulfuric acid was gradually added into the dyeing bath during 30 minutes so that the pH of the dyeing bath might be adjusted to be 3.5. The fibers were gradually cooled, were washed with water and were dried. The dye concentration on the dyed product was shown to be 98.3%. Its light-fastness Was Class 7 and its laundry-fastness was Class 5. The dyed product had been evenly dyed.

On the other hand, the same yarn was dyed by a cationic retarded dyeing method. That is to say, 2% OWF C.I. Basic Blue 3 (C.I. No. 51005) and 1% OWF cationic retarder Levegal PAN (produced by Farbeufabriken Bayer AG, Germany) were added into a dyeing bath The same sample as is mentioned above was dyed at a bath ratio of 1/ 100. After the fiber were immersed in the dyeing bath, the dyeing bath temperature was gradually elevated from 60 C. to 100 C. in 45 minutes and was then kept at 100 C. to dye the fibers. The fibers were then gradually cooled, were Washed with water and were dried. The thus dyed product showed a dye concentration of 98.5%. But its light-fastness was Class 6 and its 1aundry-fastness was Class 4. It is evident that they are inferior to the method of the present invention.

EXAMPLE 5 5% OWF of potassium azelate was added to a bath of 1% OWF of C.I. Basic Orange 27 and the pH was adjusted to 9 with sodium hydroxide. After adding 1 g./ liter Noygen HC (polyoxyethylene lauryl ether), acrylic fiber (sulfonic acid group content 0.4%) was immersed in the dyeing bath at a bath ratio of 1/100. The bath was heated from 60 C. to C. at a rate of 1 C./min. and kept at 100 C. for further 40 minutes. In ten minutes after the bath reached 100 C. dilute sulfuric acid was gradually added so that the pH became 3.5 at the end of said 40 minutes period. The fiber was cooled, washed with water and dried. The fiber was dyed evenly in deep orange and the dye concentration was 93.5%. The light-fastness was Class 7 and the laundry-fastness was Class 5.

On the other hand, the same fiber was dyed by the corresponding IT process. The dye concentration of the dyed product was 62.8%. The light-fastness was Class 7 and the laundry-fastness was Class 5.

COMPARATIVE EXAMPLE (I) A dyeing bath (1% OWF) of C.I. Basic Orange 21 (C.I. No. 48035) was added with sodium caprylate in an amount of 10% OWF and further with Noygen HC (polyoxyethylene lauryl ether) in an amount of 1 g./liter. Then the pH was adjusted with sodium hydroxide to 8, and a knit fabric of acrylic fiber (sulfonic acid group content 0.4%) was immersed in the bath at a bath ratio of l/100. The bath temperature was increased from 60 C. to 100 C. at a rate of 1 C./ min. When the temperature reached 100 C. dilute sulfuric acid was gradually added until the final pH became 3.5. The dyeing was conducted at 100 C. for 20 minutes.

(II) The same sample was'immersed in the same bath but containing only C.I. Basic Orange 21 1% OWF). The bath was heated from 60 C. to 100 C. at a rate of 1 C./min. and kept at 100 C. for 20 minutes.

(III) The procedure (I) as above was repeated except that sodium succinate was used instead of sodium caprylate.

The relation of dye concentrations C (percent) with dyeing time in each of the above (I), (II) and (1H) is shown in FIG. 2.

What we claim is:

1. A process for the coloration of acrylic fiber having sulfonic acid group which comprises immersing said fiber in a dyebath containing at least one cationic dyestutf, at least one compound selected from the group consisting of salts of saturated and unsaturated monocarboxylic acids having not less than 11 carbon atoms in the molecule and salts of saturated di-carboxylic acids having not less than 6 carbon atoms in the molecule in an amount of 5- 10% of the weight of the fibers, and a non-ionic surface active agent, adjusting the pH value of the bath to 8-9 in the initial period of the dyeing, gradually reducing the pH value of the dyebath to 3-4 in the end period of the dyeing.

2. A process as claimed in claim 1 wherein the pH is reduced by the addition of dilute sulphuric acid.

3. A method as claimed in claim 1 wherein the salts of saturated and unsaturated monocarboxylic acids and saturated dicarboxylic acids are sodium salts, potassium salts and ammonium salts.

4. A method as claimed in claim 1 wherein the saturated monocarboylic acids are undecylic acid, laulic acid, dodecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nondecylic acid and arachidic acid.

5. A method as claimed in claim 1 wherein the unsaturated monocarboxylic acids are undecenoic acid, dodecenoic acid, tetradecenoic acid, hexadecenoic acid and octadecenoic acid.

7 8 6. A method as claimed in claim 1 wherein the satu- 3,357,782 12/1967 Carbonell et a1. 855ABX rated dicarboxylic acids are adipic acid, pimelie acid, 3,436,169 4/1969 Zurbuchen et al 8-173X suberic acid, azelaic acid, sebacic acid, undecanic diacid, dodecanic diacid, brassylic acid and tetradecanic diacid.

References Cited UNITED OTHER REFERENCES I. A. Leddy, American Dyestufif Reporter, v01. 49, Apr. 5 18, 1960, pp. 272, 274, 281-284.

STATES PATENTS GEORGE F. LESMES, Primary Examiner Bidgood 85ABX T. J. HERBERT, JR., Assistant Examiner Hiller 855ABX Baumann et a1. 855AB 10 U.S. C1. X.R.

Mikula 855AB 8177 

